The invention relates to a mechanism for the separation of hot liquid materials such as mixtures of molten metals, metal compounds or metal containing slags by centrifugal force.
Various arrangements have been heretofore employed for the separation of molten or partially molten metal and metal slag mixtures, and an example of an early structure for this purpose is illustrated in German Pat. No. 80041 dated Apr. 18, 1894. However, centrifugal separation has not gained substantial importance in the metal smelting field because of various technical difficulties encountered with apparatus heretofore available.
It is significant that in a continuous recovery process, a very important step is the final separation at the end, and if this does not adequately function, it inhibits the satisfactory operation of the entire process. To be satisfactory for continuous operation in a continuous metal recovery process, the separator must be absolutely reliable and sturdy, and must be capable of functioning under high loads with high temperature ranges, must be capable of resisting corrosion and wear and must be capable of continuous operation for long periods of time and must be capable of operation safely without requiring shut-down of the process for servicing and replacement, and if such shut-downs are necessary, replacement of parts must be done quickly and reliably.
It is accordingly an object of the present invention to provide an improved metal and slag separator which avoids disadvantages present in structures heretofore available, and provides a unit capable of safe and continuous reliable operation for use in a continuous metal refining process.
In accordance with the principles of the invention, a centrifugal separator is provided constructed of a plurality of layers arranged in a sandwich type construction so that an annular housing is provided having an outer wall which has a removable insert in its interior arranged concentrically spaced from the outer wall and supported with axially spaced mountings within the outer wall and separated therefrom by a layer of insulation. Within the sleeve insert is a casing which is adapted to contact with the molten metal and is held concentrically within the sleeve by spaced holders. Advantages of such a multilayer construction for a centrifugal separator reside in that each layer can perform to its optimum function, and the layers act in concert as a unit to provide as an entity a resultant unit having capabilities which exceed the sum of the individual capabilities of the layers. The individual selection of the layers is in accordance with the particular purpose and function required, and with this arrangement, the possibility is afforded of rapid interchangeability and replacement of a layer. In accordance with the arrangement, separate replacement and separability is possible for the insert sleeve as well as the insert casing, and a rapid separation mount and connection is provided therefor.
The function of the sleeve in combination with an insulation layer and the outer wall is for support and for heat insulation. By contrast, many devices heretofore available utilized a fire-proof mass, and the instant arrangement provides a relatively lightweight layer of mineral wool. This has an advantage in that it possesses an insulating effect superior to known fire-proof preparations and is substantially lighter. The outer wall has mechanical strength for carrying and connecting to the rotating drive and rotating support, and does not have to be of superior heat resistant material. This outer wall is made, for example, of boiler plate ST 52. The insert sleeve is preferably of a heat-proof material such as chromium steel, and the inner casing formed of a heat and corrosion resistant material such as UMCO 50 (50% Co., 27% Cr, and 23% Fe).
For supporting the inner casing within the insert sleeve because of the possibility of elastic deformation with extreme heat load, spaced holders are arranged circumferentially and axially separated formed of sheet metal elements of the same material as the inner casing.
An advantage of the construction is that it affords flexibility of the layers with respect to each accommodating the stresses occuring with heat expansion. The mounting and support of the unit is such that it has no exactly defined center of gravity, and the design and construction does not have to be critical in this respect, and this is particulary true since this location of the center of gravity changes with continual operation as it is filled and processes molten metal and slag. The advantage of this arrangement is utilized by suspending the unit on a universal or gimbal ring support at its upper end to permit free oscillation about the actual or natural center of gravity, which arrangement has not been employed in the separation of molten metals in a continual process system. With structures heretofore available, a relatively cumbersome conventional type of rigid support has been necessary increasing the cost and weight, and resulting in imbalances during operation, expensive construction due to attempts to obtain a complete original construction balance and increased wear and interruption with the necessity of having an absence of lateral or radial vibrations and disruption during centrifugal separation.
Other objects, advantages and features will become more apparent, as well as equivalent structures which are intended to be covered herein, with the teaching of the principles of the invention in connection with the disclosure of the preferred embodiment in the specification, claims and drawings in which: